Helicobacter pylori are related to gastric cancer. After screening of antimicrobial activities from various plants methanol extracts against H. pylori KCTC2948, we found Reynoutria elliptica methanol extract and further fractions have significant antibacterial effects especially hexane fr. and CHCl₃ fr. The growth inhibition effects on the gastric cancer cell lines such as KatoIII and AGS cells were investigated with MTT. After 48 hr treatments R. elliptica extracts and fractions were shown growth inhibition upto 70∼80% at 0.4∼1 mg/ml concentrations. The growth inhibition effects was higher AGS than KATO III. We applied comet assay to measure the DNA damage in the individual cells and exposed time course at IC₅₀. All fractions have shown to time dependent on DNA damage and these fractions also observed higher than 80% in DNA strand breaks. These DNA strand breaks were transient, reaching a maximum level after 2 hr of exposure. In conclusion, we found that R. elliptica has in vitro growth-inhibiting and apoptosis- inducing effects on gastric cancer cells.

Keywords: Helicobacter pylori, Reynoutria elliptica, Comet assay, DNA damage